Cutting forces for PVC extrusion using a shearing blade

[CN-SEE-YA]

Hi Guys.

I am trying to cut a rectangle out of some flexible PVC extrusion that is 4.5mm thick. the rectangle is 150 x 100 and I am using a shearing blade that is 1mm thick.
How do I calculate the force needed to cut through the extrusion?

[routercnc]

It’s been along time since I did calculations like this so this could be well off !

I think I would start with the shear modulus of PVC which is 12-115 N/mm2. Let’s take worst case 115N/mm2

Multiply this by the shear area which is 2x(150x4.5)+2x(100x4.5)

This assumes a rectangular cookie cutter style blade pressing down with a female tool with the a hole in it supporting the underside of the area to be cut

This should give the shearing force I think. Try it and see !

Ps I don’t think the blade width comes into play so long as it can apply the force without bending or damage.

Happy to be corrected on the above!

[CN-SEE-YA]

So the calculation comes out at 2250, am I to assume that means 2and a quarter tons pressure?

[routercnc]

The results come out in Newton’s of force required. But please don’t spend money on the outcome of the above calculations because it has been a long time since I did that type of stuff. Ask around and maybe try something out first with what you have to check it is correct.

[CN-SEE-YA]

Many thanks routercnc.